The Highly Active, Highly Sensitive Brain at-Rest
11th August 2021 - By Bianca P. Acevedo, PhD
About the authors
Bianca Acevedo (University of California, Santa Barbara) researches the biology of love, high sensitivity and mind-body practices. She was the recipient of the 2012 International Women in Science Award and is Editor of “The Highly Sensitive Brain.” For more information visit http://www.biancaacevedo.com
In a recent study, my colleagues and I examined resting-state brain connectivity in relation to sensory processing sensitivity (SPS). We found that the more sensitive individuals showed stronger resting-state brain connectivity indicative of greater memory and higher-order deliberative processing. This study advances our understanding of the highly sensitive brain’s central features.
Have you ever wondered if you or someone you know might be highly sensitive? Approximately one in four people (20%-30% of the population) are characterized by high sensory processing sensitivity (SPS), or environmental sensitivity (ES).
High sensitivity is characterized by an increased awareness and sensitivity to the environment and others. A highly sensitive person — whether child or adult — processes stimuli and information more deeply than those less sensitive.
Individuals with high sensitivity express these cardinal features:
- Deeper cognitive processing
- More attention to subtleties
- Pausing before acting
- Greater awareness of environmental and social stimuli, including the moods and emotions of others
In a recent study (1), published in the journal Neuropsychobiology, my colleagues (Drs. A and E. Aron, R. Marhenke, and T. Santander) and I examined resting-state brain connectivity as a function of sensitivity, measured with the Highly Sensitive Person (HSP) Scale (2).
This was the first study to investigate what the highly sensitive brain does at-rest.
We scanned a group of adult participants (M age = 66 yrs.) at the University of California, Santa Barbara’s Brain Imaging Center (BIC), with a Siemens magnet functional MRI which detects changes in blood flow of the brain.
First, our participants engaged in an emotionally evocative task where they were asked to read descriptions of happy, sad or neutral events, followed by corresponding emotional faces of their partners and of strangers.
We also instructed them to count backwards by 7s from a large number, to wash away the effects of experiencing any kind of emotion between the facial photo displays. After the scan, but while still in the scanner, we asked each participant to rate how they felt while viewing each face image.
Finally, we asked our participants to simply relax for 5-minutes, while we measured their brain activity as they rested.
What we found was that after engaging in an emotionally evocative task, the more sensitive individuals (those that scored higher on the HSP Scale) showed stronger resting-state connectivity in areas suggesting greater depth of processing.
For example, one of the most robust connections that we found to be associated with the highly sensitive brain while resting was the precuneus-hippocampus circuit.
Connectivity between the precuneus and hippocampus has been implicated in episodic memory consolidation and spontaneous memory retrieval.
The consolidation of memory is important for preparing an individual/organism for future similar situations, appropriate/adaptive responsiveness, and also to place the new information in relation to already existing information. Thus, memory plays a central role in depth of processing.
However, weaker connections were found between the hippocampus and the insula, suggesting higher order, deliberative consolidation of memory, rather than the habitual, automated responses which are usually triggered by stressful events.
What does this all mean?
In sum, the highly sensitive brain at-rest is actually deep at work, helping individuals to integrate information, so they can remember it and be well-equipped to navigate the intricacies of their environments. So, lighten up and take a break. You’ll be surprised how when you retreat into your inner world and a restful state, that things start to flow.
The results of this paper represent just one step in better understanding sensory processing sensitivity, and its biological underpinnings. We still have much work to do.
If you are curious to learn more about the science of SPS, feel free to take a look at “The Highly Sensitive Brain,” a finalist for the 2021 Association of American Publishers Professional and Scholarly Excellence (PROSE) Award in Neuroscience, and which will be featured in the 2021 American Psychological Association’s (APA) conference.
- Acevedo B, P, Santander T, Marhenke R, Aron A, Aron E (2021). Sensory Processing Sensitivity Predicts Individual Differences in Resting-State Functional Connectivity Associated with Depth of Processing. Neuropsychobiology, 80:185-200. doi: 10.1159/000513527
- Aron E. & Aron A. (1997). Sensory-processing sensitivity and its relation to introversion and emotionality. J Pers Soc Psychology, 73(2): 345–68